1) Can only grade between AG-3 & VG-10.
2) Must have nice, original color.
3) Can NOT have ANY dings, gouges or scratches that may detract from the overall appearance.
4) Should have been 'born' a well-struck coin to begin with (sometimes hard to determine).
Here's one example (photographed through a slab -- ANY imperfections are in the plastic and NOT on the coin's surface). I'm sure everyone has some of these in their collections. SHOW US!!!
